Editing French Republican calendar (section)

== Criticism and shortcomings ==
[[File:Horloge-republicaine1.jpg|thumb|Clock dial displaying both decimal and duodecimal time]]
Leap years in the calendar are a point of great dispute, due to the contradicting statements in the establishing decree<ref name="gefrance.com">{{cite web |date=30 May 2020 |title=Le Calendrier Republicain |url=https://gefrance.com/the-french-republican-calendar/ |url-status=live |archive-url=https://web.archive.org/web/20210624222613/https://gefrance.com/the-french-republican-calendar/ |archive-date=24 June 2021 |access-date=25 June 2021 |publisher=Gefrance.com}}</ref> stating:

{{blockquote|Each year begins at midnight, with the day on which the true autumnal equinox falls for the [[Paris Observatory]].}}

and:

{{blockquote|The four-year period, after which the addition of a day is usually necessary, is called the ''Franciade'' in memory of the revolution which, after four years of effort, led France to republican government. The fourth year of the ''Franciade'' is called ''Sextile''.}}

These two specifications are incompatible, as leap years defined by the autumnal equinox in Paris do not recur on a regular four-year schedule. It was erroneously believed that one leap day would be skipped automatically every 129 years,<ref>{{Cite web |title=Instruction sur l'ère de la République, à la suite du décret du 3 brumaire, an II |url=https://documents.univ-toulouse.fr/150NDG/PPN042658012.pdf |url-status=live |archive-url=https://web.archive.org/web/20231216162245/https://documents.univ-toulouse.fr/150NDG/PPN042658012.pdf |archive-date=16 December 2023 |access-date=27 November 2023 |website=Université de Toulouse}}</ref> on average, but actually five years would sometimes pass between leap years, about three times per century. Thus, the years III, VII, and XI were observed as leap years, and the years XV and XX were also planned as such, even though they were five years apart.
[[File:Horloge-republicaine2.jpg|thumb|Clock dial displaying both decimal (inside the circle) and duodecimal time (on the outer rim)]]

A fixed arithmetic rule for determining leap years was proposed by Delambre and presented to the Committee of Public Education by Romme on 19&nbsp;Floréal&nbsp;An&nbsp;III (8 May 1795). The proposed rule was to determine leap years by applying the rules of the Gregorian calendar to the years of the French Republic (years IV, VIII, XII, etc. were to be leap years) except that year 4000 (the last year of ten 400-year periods) should be a common year instead of a leap year. Shortly thereafter, Romme was sentenced to the guillotine and committed suicide, and the proposal was never adopted, although [[Jérôme Lalande]] repeatedly proposed it for a number of years. The proposal was intended to avoid uncertain future leap years caused by the inaccurate astronomical knowledge of the 1790s (even today, this statement is still valid due to the uncertainty in [[ΔT (timekeeping)|ΔT]]). In particular, the committee noted that the autumnal equinox of year 144 was predicted to occur at 11:59:40&nbsp;pm [[local apparent time]] in Paris, which was closer to midnight than its inherent 3 to 4&nbsp;minute uncertainty.

The calendar was abolished by an act dated 22 Fructidor an XIII (9 September 1805) and signed by [[Napoleon]], which referred to a report by [[Michel-Louis-Étienne Regnaud de Saint-Jean d'Angély]] and [[Jean Joseph Mounier]], listing two fundamental flaws.
# The rule for leap years depended upon the uneven course of the sun, rather than fixed intervals, so that one must consult astronomers to determine when each year started, especially when the equinox happened close to midnight, as the exact moment could not be predicted with certainty.
# Both the era and the beginning of the year were chosen to commemorate a historical event that occurred on the first day of autumn in France, whereas the other European nations began the year near the beginning of winter or spring, thus being impediments to the calendar's adoption in Europe and America, and even a part of the French nation, where the Gregorian calendar continued to be used, as it was required for religious purposes.
The report also notes that the 10-day décade was unpopular and had already been suppressed three years earlier in favor of the seven-day week, removing what was considered by some as one of the calendar's main benefits.<ref>{{cite book |author=Antoine Augustin Renouard |url=https://books.google.com/books?id=oUoMAAAAIAAJ |title=Manuel pour la concordance des calendriers républicain et grégorien: ou, Recueil complet de tous les annuaires depuis la première année républicaine |date=1822 |publisher=A. A. Renouard |edition=2 |page=217}}</ref> The 10-day décade was unpopular with laborers because they received only one full day of rest out of ten, instead of one in seven, although they also got a half-day off on the fifth day (thus 36 full days and 36 half days in a year, for a total of 54 free days, compared to the usual 52 or 53 Sundays). It also, by design, conflicted with Sunday religious observances.

Another criticism of the calendar was that despite the poetic names of its months, they were tied to the climate and agriculture of [[metropolitan France]] and therefore not applicable to [[Overseas departments and territories of France|France's overseas territories]].<ref>{{Cite book |last=Canes |first=Kermit |title=The Esoteric Codex: Obsolete Calendars |publisher=LULU Press |year=2012 |isbn=978-1-365-06556-9}}</ref>